DESCRIPTION: (Applicant's Description) The specific aims of this research are: 1) To compare mammography screening practice, clinical management, and screening outcomes for the women over age 40 in the 24 county population with special reference to differences in Black versus White, urban versus rural, <50 versus >50, and the subset of women receiving mammography funded through the BCCCP versus the general population of screened women for the years 1995-2000; and 2) To describe the distribution and mammographic characteristics of benign pathology by race, age, and other characteristics to raise hypotheses for further research. Two additional projects are proposed based on the identification of interval and screen detected cancers in this population. The specific aims of these projects are: 1) to assess the image quality of the mammograms of interval cancers compared to screen detected cancers; and 2) to compare the histochemical characteristics of interval versus screen detected cancers. The creation of a population based mammography registry in 24 counties in eastern North Carolina. a population that has a high proportion of Black and rural women, gives us the opportunity to do breast cancer surveillance research using the data collected from 79 mammographic practices in this area. This data is linked to a population based pathology database, and the North Carolina Central Cancer Registry (NC CCR). Analyses will be conducted on the population accrued by the Carolina Mammography Registry for the time period January 1995 through December 2000. Women will be enumerated beginning with their screening mammogram, and their outcomes will be determined through two mechanisms: 1) radiologic follow up from registry linked data; and 2) follow up efforts aimed at the referring physicians. Chi square analyses will be carried out testing proportional data; t tests will be used for comparisons of means; and logistic regression analyses will be carried out when appropriate.